Viacom has been an early mover in upfront negotiations with ad buyers for the past several seasons, writing business in the days following broadcast presentations by offering what it believes to be more favorable terms to drive volume. But this year, it appears deal-making at cable network group, which owns Nickelodeon, MTV and VH1, among others, has gotten off to a slow start.

Historically, Viacom hasn't placed a lot of emphasis on increases in advertisers' cost to reach a thousand viewers, an industry standard known as CPMs, sometimes sacrificing on price to bring in additional business.

Media buyers suggested that Viacom may have started doing some deals quietly, but for the most part negotiations don't seem as far along as they were in previous years.

Viacom is entering the annual upfront marketplace, where buyers will make commitments for ad time in networks' upcoming programming, in a stronger position than in recent history. Nickelodeon, which had struggled with viewership declines, has since seen 15 consecutive months of ratings improvement. The company has also been aggressive in rebuilding both VH1 and MTV with new programming.

While it is early to tell exactly how negotiations will progress, and Viacom isn't viewed as a market mover, the slow start for a usual early mover could indicate that the upfronts will be drawn out.

Overall, the upfront marketplace has been quiet.

"We were very active and had deals done by this point last year," one media buyer said.

Another industry insider said conversations with clients so far are taking longer, but that the market could break very soon.

Media buyers said they expect the amount of dollars that advertisers plan to allocate to upfront commitments to be flat or slightly down from last year.